Your question really doesn't work on either case.
Why are you buying a new converter?
Whats wrong with your flex plate that makes you want a new one?
Are you asking about a high stall converter over a OEM stall?
Can't answer cost on cab mount without seeing the damage and what needs replacement.
Way to generic of questions.

And these trucks don't have a flex plate stock... it has a flang that blots to the cranks that blots to the converter...Two of the bolts were broke off in it and it acts like it has a high stall in it when you take off after start up but not when you let it warm up and I bent a cab mount on the frame when I was going through a trail and just wanna know if it could be straightened or replaces so the cab isnt saggin to one side

Ok. So your flex plate is pooched. Sorry, flange. And your converter is pooched. So you want to know what?
New oem or aftermarket oem?
Im a welder/Fabricator. Company charges $100/hr. Cab mount sight unseen and no information. Two days labour plus parts. Lets say $2500.
A bit high maybe but it answers your question.

I just was wondering if anyone has put a aftermarket converter in their dakota.

Thats not really what I want to here but it is what it is I guess... could nobby mud tires cause enough vibration in the drive line to work them loose or is that just my guts saying the trans is fine.... lol and thats what I wanted to know about the mount, thanks!

I just was wondering if anyone has put a aftermarket converter in their dakota.

Thats not really what I want to here but it is what it is I guess... could nobby mud tires cause enough vibration in the drive line to work them loose or is that just my guts saying the trans is fine.... lol and thats what I wanted to know about the mount, thanks!

what I meant is that convertors are welded inside, the blade angles can't change. The only way a convertor itself can slip is if it tried to go into lockup, and the lockup clutch comes apart. BTDT. Wiped out whole trans from filling it with clutch dust.

The internal bands and clutches in the trans are what typically slip, either from reduced line pressure (line pressure keeps the clutches pressed together) due to a failing pump, or due to an eroded or otherwise loose band. Either way introduces loose material into the trans which can clog the solenoids and check ***** in the valvebody, leading to terminal failure.

In my case, I had a cracked drum, wasted O/D clutch, 2 clogged solenoids, a worn out clutch pack, and a band at half-life. I had to have it towed because I lost O/D, then drive, then second, then first and reverse. Yea, that wasn't a pretty tow+repair bill.